Metastable phase formation and high coercivity of Nd90F 10 by gas flow type levitating process

Hiroshi Yonemura, Shuji Azumo, Katsuhisa Nagayama

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

In the last decades, Nd-Fe amorphous alloys have been studied by many methods because of high coercivity at room temperature and relation to Nd-Fe-B permanent magnets. In this study, we examined the effect of the containerless process for high undercooling and the metastable phase formation in detail. In the gas levitating process, undercooling of Nd90Fe10 samples increased with cooling rate. Undercooling of Nd90Fe 10 sample solidified at 268 K/s is ΔT= 35 K. The primary α-Nd phases were surrounded by fine metastable phases. And the intergranular eutectic-like areas were comprised of α-Nd phase and metastable phase. In contrast, the sample with low undercooling was comprised of α-Nd phases and rod-like Nd2Fe17 phases among primary α-Nd phases. In Nd90Fe10 samples with undercooling of Δ T= 35 K, coercivity of Nd90Fe10 samples is about 4.5 kOe at room temperature. This high coercivity is caused by fine crystallization of matastable phases.

Original languageEnglish
Pages (from-to)80-84
Number of pages5
JournalNippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals
Volume72
Issue number2
DOIs
Publication statusPublished - 2008 Feb

Fingerprint

Undercooling
Metastable phases
supercooling
Coercive force
coercivity
gas flow
Flow of gases
Amorphous alloys
room temperature
Crystallization
permanent magnets
eutectics
Eutectics
Permanent magnets
rods
Gases
crystallization
Cooling
cooling
Temperature

Keywords

  • Containerless process
  • Gas jet levitating process
  • High coercivity
  • Neodymium-iron system metastable phase
  • Nucleation
  • Undercooling

ASJC Scopus subject areas

  • Metals and Alloys

Cite this

Metastable phase formation and high coercivity of Nd90F 10 by gas flow type levitating process. / Yonemura, Hiroshi; Azumo, Shuji; Nagayama, Katsuhisa.

In: Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, Vol. 72, No. 2, 02.2008, p. 80-84.

Research output: Contribution to journalArticle

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